public static DigitalSignature FromKey(byte[] privateKey, byte[] publicKey)
        {
            if (privateKey == null || privateKey.Length != 32)
            {
                return(null);
            }
            if (publicKey == null || publicKey.Length != 64)
            {
                return(null);
            }

            var param = new ECParameters()
            {
                Curve = ECCurve.CreateFromFriendlyName("secp256k1"),
                D     = privateKey,
                Q     = new ECPoint()
                {
                    X = publicKey.Take(32).ToArray(),
                    Y = publicKey.Skip(32).Take(32).ToArray(),
                },
            };

            var ds = new DigitalSignature(privateKey, publicKey);

            try
            {
                ds.dsa = ECDsa.Create(param);
            }
            catch
            {
                return(null);
            }

            return(ds);
        }
        public static DigitalSignature Generate()
        {
            var dsa = ECDsa.Create("ECDsaCng");

            dsa.GenerateKey(ECCurve.CreateFromFriendlyName("secp256k1"));
            var param = dsa.ExportParameters(true);

            var ds = new DigitalSignature(param.D, param.Q.X.Concat(param.Q.Y).ToArray());

            ds.dsa = dsa;

            return(ds);
        }